a quantum chemical study of the corrosion inhibition properties of some organic inhibitormolecules, pyridine, 2-picoline, 3-picoline, 4-picoline, 2, 4-lutidine at the aluminum surface inhydrochloric acid (hcl) was carried out. the models of the inhibitors adsorption on the al-surfacewere optimized with the hf and b3lyp level using the 6-31g and lanl2dz basis sets fromthe program package gaussia...

in this paper,the molecular geometry for three tautomers of uracil and four tautomers of cytosine has been analyzed. vibrational ir spectra of the tautomers were   investigated at hf and b3lyp level using the ab initio 6-31g* and lanl2dz basis sets from the program package gaussian 98 (a.7 public domain version). the physico-chemical and biochemical properties of uracil and cytosine are one of...

ab initio and dft methods have been used to study the seven tautomeric forms of 5-methylcytosine molecule.the related tautomer in gas phase have been studied at hf/6-31g, hf/6-31g* and b3lyp/6-31g* levels oftheory. the structures,enthalpies,entropies,gibbs free energies,relative tautomerization energies of tautomersand tautomeric equilibrium constants were compared and analyzed along with full ...

Nowadays NMR spectroscopy becomes a powerful tool in chemistry because of the NMR chemical shifts. Hartree–Fock theory and the Gauge-including atomic orbital (GIAO) methods are used in the calculation of 29Si NMR chemical shifts of various silicate species in the silicate solution as initial components for zeolite synthesis both in gas and solution phase. Calculations have been performed at geo...

the potential energy surface of gaseous glycine determined years ago in the ab initio b3lyp/6-311++g** calculations is composed of thirteen stable conformers. we performed the ab initiomolecular orbital calculations as the starting point to carry out a force field and normal coordinatecalculation on the most stable conformer of non-zwitterionic glycine [conformer (i)]. thecalculations were carr...

the interaction of fe2+ ion with pyrazole was theoretically studied by gussian 03, software at hf/(lanl2dz+6-31g) and hf/ (lanl2dz+6-31g (d)) levels in gas phase and solution. in this study acompartion between optimized structures of pyrazole molecule in aspect of thermodynamicparameters such as enthalpy (h°), gibbs free energy (g°) and entropy (s°) in presence of metallic ion(fe2+), was perfor...

Ab initio all-electron molecular-orbital calculations are carried out to study the structures and relative stability of low-energy silicon clusters (Si(n),n = 12-20). Selected geometric isomers include those predicted by Ho et al. [Nature (London) 392, 582 (1998)] based on an unbiased search with tight-binding/genetic algorithm, as well as those found by Rata et al. [Phys. Rev. Lett. 85, 546 (2...

A quantum chemical study of the corrosion inhibition properties of some organic inhibitormolecules, pyridine, 2-picoline, 3-picoline, 4-picoline, 2, 4-lutidine at the aluminum surface inhydrochloric acid (HCl) was carried out. The models of the inhibitors adsorption on the Al-surfacewere optimized with the HF and B3LYP level using the 6-31G and LANL2DZ basis sets fromthe program package Gaussia...